It is often necessary, due to various spinal disorders, to surgically correct and stabilize spinal curvatures, or to facilitate spinal fusion through an open approach or through a minimally invasive approach. Numerous systems for treating spinal disorders have been disclosed. One known method involves a pair of elongated members, typically rods, longitudinally fixed to the posterior spine on either side of spinous processes of the vertebral column. Each rod is attached to various vertebrae along the length of the spine by engaging bone fixation elements to the vertebra and fixing a rod to the bone fixation elements. The bone fixation elements commonly include a U-shaped rod-receiving channel for receiving the rod therein. Moreover, the rod-receiving channel often interacts with a locking cap to clamp and fix the position of the rod with respect to the bone fixation element.
Surgeons may have difficulty aligning the rod(s) within the rod-receiving channels formed in the body of the bone fixation elements. For example, the body of the bone fixation elements may be out of vertical and/or horizontal alignment with one another due to the curvature of the spine or the size and shape of each vertebra.
Thus, it is desirable to construct an apparatus to facilitate insertion of the longitudinal rods into the rod-receiving channels formed in the bone fixation elements and to derotate the spine.